The present invention relates to machines for filling caulking tubes with liquid compositions and more particularly the present invention relates to an improved manifold for feeding plunger caps to a caulking tube machine for filling caulking tubes with liquid compositions.
Caulking tube filling machines are well known as well as the caulking tubes themselves. Generally, caulking tubes have a cylindrical body with a plunger cap at one end and a protruding nozzle at the other end. When it is desired to utilize the caulking tube, the tip of the nozzle is cut, the caulking tube is put in the caulking gun, and a ram is activated against the plunger at the rear end of the caulking tube so as to force the composition out of the cut portion of the nozzle of the caulking tube. Generally, there is packaged in such caulking tubes liquid compositions which it is desired to keep from the elements such as, atmospheric moisture, prior to cure and prior to use.
Accordingly, in the case of one-component room temperature vulcanizable silicone rubber compositions, such compositions are packaged in caulking tubes such that the caulking tube keeps atmospheric moisture from entering the caulking tube. As long as atmospheric moisture is not allowed into the caulking tube, the resulting composition in the caulking tube does not cure. However, upon being applied by the method outlined previously, the composition when exposed to atmospheric moisture will cross-link and cure to a silicone elastomer. Such one-component room temperature vulcanizable silicone rubber compositions are useful as sealant compositions, both in construction and industrial applications. Such caulking tubes are filled in caulking tube filling machines. However, it should be noted that the instant invention is not limited solely to caulking tube filling machines for room temperature vulcanizable silicone rubber compositions, but can be applied to any caulking tube filling machines such as, a caulking tube filling machine for filling cheeses and other foods into cartridges for one application or another.
An example of a desirable caulking tube filling machine is to be found in FIG. 1, which generally comprises a frame with a motor which drives a main shaft which drives the appropriate upper shaft through appropriate linkage means. The appropriate upper shaft drives six pistons and cylinders which take measured quantities of liquid composition from the two reservoirs on top of the machine and then later through the appropriate linkages and mechanisms (not shown in FIG. 1), and deposit the measured quantities of liquid composition through passage tubes into the empty caulking tubes that are positioned on a conveyor belt.
It should be noted that one main characteristic of the apparatus of the present invention (as seen in FIG. 1) versus the apparatus of the prior art, is that the apparatus of the present invention (as seen in FIG. 1) is capable of reliably and consistently filling six caulking tubes at a time, while prior art caulking tube filling machines were much more complicated in their cap feed mechanism. The distinction with regard to the advantages of the present invention for putting six caps at a time at the rear end of filled caulking tubes will be discussed below. Suffice to state that mechanisms such as that shown in FIG. 1, were capable and are capable of filling four caulking tubes at a time with liquid composition which was in the reservoirs located at the top of the frame of the apparatus in FIG. 1, which mechanisms are partly hidden in FIG. 1, with measured quantities of liquid composition. The mechanism for filling the caulking tubes which is explained in the copending cases will not be discussed here in detail since it forms no part of the instant invention of this case.
The filled caulking tubes will then travel from the viewer into the plane of the paper into a cap-receiving structure which will reciprocate and take caps as they were fed into it from a cap manifold and position them six at a time on top of the filled caulking tubes, as seen in FIG. 2. Then six air activated pistons will ram the plungers into the appropriate position in the caulking tubes. The six pistons would then retract and the caulking tubes would then pass from the placing of the plunger position to a further position in the apparatus where they would be packaged and shipped from the manufacturing plant.
It was important in this part of the operation of the apparatus which the present case is concerned with, that is, the placing of the plunger caps into the rear end of the filled caulking tubes, that the cap manifold feed the caps properly into the cap-receiving structure for being positioned effectively over the filled caulking tube so that the air activated piston could ram the plunger cap into the back side of the filled caulking tube thus forming a seal.
An example of a prior art plunger cap manifold for feeding plunger caps into the cap-receiving means of the structure shown in FIG. 2, is shown in FIG. 3. Generally, such a plunger cap feed manifold comprises a central chute from an overhead vertical position which gradually branches out to four separate feed chutes which feed chutes slope gradually from a vertical to a horizontal position at the point where the four feed chutes meet the cap-receiving structure means of FIG. 2. The manifold plunger cap feed structure, as that shown in FIG. 3, operated in some respects with efficiency for a machine capable of filling four caulking tubes at a time. However, it would have some problems or disadvantages in that occasionally it would jam such that plunger caps would not come out of one or more of the chutes so that they could be positioned directly over the filled caulking tubes to be pushed into place by the air driven piston, which would result in the air driven piston forcing itself into the liquid composition in the filled caulking tube creating a mess and also creating one or more caulking tubes which had to be discarded until the jamming was corrected.
It was found that a plunger cap manifold structure, such as shown in FIG. 3, could operate better by having air pressure forced against the upper plunger caps in the vertical part of the structure. This would create sufficient pressure so that the plunger caps would feed themselves into the appropriate positions over the filled caulking tubes in the plunger cap-receiving structure. However, even then occasionally such plunger caps would jam in one or more chutes in the manifold plunger cap structure of FIG. 3. However, when this same structure was taken and tried to be applied so that there would be six chutes coming off in the same general configuration, as shown in FIG. 3, so that the manifold could feed six plunger caps at a time into the cap-receiving structure of the caulking tube filling machine, then even with air pressure such an apparatus would frequently jam and would work poorly. Accordingly, it was highly desirable to design a manifold structure which could feed plunger caps to the cap-receiving structure in the caulking tube filling machine at the appropriate rate and six at a time so as to be placed over six filled caulking tubes at a time with facility and efficiency and without the plunger caps jamming in the manifold.
It was also desirable to simplify the structure of the coupling in the cam structure as well as the cam follower in the drive means for driving the cap-receiving structure of a caulking tube filling machine in accordance with the instant invention.
Accordingly, it is one object of the present invention to provide for a simple but efficient manifold structure for feeding six plunger caps at a time to the cap-receiving structures of a caulking tube filling machine.
It is an additional object of the present invention to provide for a manifold for feeding six plunger caps at a time to a cap-receiving structure without the plunger caps jamming in the manifold structures.
It is still an additional object of the present invention to provide for a simple structure for combining the coupling from a main drive shaft of a caulking tube filling machine with a cam and cam follower linkage in the linkage means that drives the cap-receiving structure means of a caulking tube filling machine.
These and other objects of the present invention are accomplished by means of the disclosure set forth in the Figures below.